From Antarctic DNA to stress tolerant crop plants – exploiting the why protein domain

Screening of an Antarctic soil functional fosmid metagenomic library identified a novel bacterial gene, homologous to known Water Hypersensitivity (WHy) domains. The WHy domain is a typical component of Late Embryogenesis Abundant (LEA) proteins which occurs widely in both prokaryotes and in plant eukaryotes and are expressed under various stress conditions [1]. A phylogenetic analysis of multiple WHy homologues from different species suggested that the ancestral origin of this protein gene lies within the ancient archaea [1]. Our previous studies have shown that this bacterial protein elicits significant protection against freeze and cold stress in recombinant E. coli [2]. Expression of the WHy gene in Arabidopsis resulted in a wide range of statistically significant stress-tolerant phenotypic properties. These included an increase of up to 6-fold higher germination efficiency of transgenic recombinant seeds compared to the WT, and a 100 % survival rate of WHy gene-expressing plants compared to 0 % survival of adult WT plants after freeze shock. Similar improvements in survival rates were observed for recombinant plants in drought stress experiments.